I think there is a giant one down in the Ft Lauderdale area.
Here's a listing for some in the Orlanod area - seems that so many of them nowadays are just retail shops inside. I haven't been to any of these
so I can't attest to their *quality*.
Flea Markets in Orlando
There is a really nice & big antique market in Mt. Dora called Renningers - fairly closeby - they have an even bigger Extravaganza
three times a year (Jan/Feb/Nov).
Renningers Florida Mt. Dora, Antiques and flea market